In assembly work of a product such as an aircraft or a ship, work (for example, assembly work of a main wing of an aircraft and the like) performed by the workers is analyzed and classified into multiple work contents (for example, drilling work, screwing work, and the like). Standard work times are then determined for the respective work contents and work processes are thereby managed.
When the workers become skilled in the work, they can perform work in a shorter time. Moreover, there is a difference in work time depending on the skills of the workers. Accordingly, the standard work times of the respective work contents need to be updated each time the work is performed. Conventionally, there are the following two types of methods for updating the standard work times of the respective work contents.
The first method is a method for updating the standard work times of the respective work contents on the basis of work times of the work contents which are recorded by an observer or a classifier different from the workers. Specifically, the observer beside the workers observes work states of the workers and thereby measures and records the work times of the work contents by using a stopwatch or the like. Alternatively, the work of the workers is recorded by a camera or the like. Thereafter, the classifier analyzes the recorded work, classifies the recorded work into multiple work contents, and records the work times of the work contents. The standard work times of the respective work contents are then updated based on the work times of the work contents recorded by the observer or the classifier.
The second method is a method for updating the standard work times of the respective work contents on the basis of the work times of the work contents which are declared by the workers. Specifically, in a work process having predetermined work contents and work procedures thereof (the execution order of the work contents), each of the workers classifies the work contents while performing the work and records and declares the work times of the respective work contents by using a stopwatch, a PDA (Personal Digital Assistant) being a mobile information terminal, and the like. The standard work times of the respective work contents are then updated based on the declared work times of the work contents.
A conventional standard work time updating system using a stopwatch is described based on FIGS. 15 and 16. Part (a) of FIG. 15 is a configuration diagram of the conventional standard work time updating system, Part (b) of FIG. 15 is an enlarged view of the stopwatch, and Part (c) of FIG. 15 is an enlarged view of a display screen of the stopwatch. Moreover, FIG. 16 is a block diagram of the conventional standard work time updating system.
As shown in Part (a) of FIG. 15, an inside of an assembly station 1 in which assembly work of a product such as an aircraft or a ship is performed is divided into multiple (four in the illustrated example) work areas 2A, 2B, 2C, 2D, and 2E for respective multiple work contents. Workers 8 perform work of the work contents in the work areas 2A to 2E. At this time, in the work areas 2A to 2E, each of the workers 8 operates a stopwatch 3 carried by the worker 8 to record work time points (work start time point and work completion time point) of the work contents in a storage device included in the stopwatch 3 and thereby declares the work time points. As shown in Parts (b) and (c) of FIG. 15, the work content and the work time point (work start time point and work completion time point) are displayed in a display screen 4 of the stopwatch 3.
As shown in Parts (a) to (c) of FIG. 15 and FIG. 16, the work time points (work start time point and work completion time point) of the work contents which are recorded by using the stopwatch 3 are transmitted to a work time management server (personal computer) 5. The work time management server 5 includes a storage unit 6 in which the work procedures, the work contents, the standard work times, and the work areas are stored as a database and a standard work time calculation unit 7.
The standard work time calculation unit 7 obtains the work times (work completion time point−work start time point) of the work contents from the work time points (work start time point and work completion time point) of the work contents inputted from the stopwatches 3 of the workers 8, calculates an average value or the like of the work times for each of the work contents, and sets the calculated value as the standard work time of the work content. Then, when the calculated standard work times of the work contents are shorter than the standard work times of the work contents which are stored in the storage unit 7 as the database, the standard work time calculation unit 7 updates the standard work times of the work contents to the standard work contents of the work contents which are calculated by the standard work time calculation unit 7 and outputs the updated standard work times.
The Patent Document 1 listed below is given as an example of a prior art document disclosing a technique in which the workers each measure the work times of the respective work contents by using the stopwatch.